NG traction motors

Remember that EMD only had maybe at most three traction motors and three traction generators/alternators in production at any one time. For GE on the other hand, traction motors was just a small part of their overall electrical motor business - so they had several advantages. GE many decades of experience before EMD even built their first traction motor (reportedly a copy of a GE design), GE had been supplying large traction motors for heavy electrics long before diesel-electrics needed any with that capacity, between mining, hoisting and locomotive production they had maybe a dozen traction motors and main generators in regular production in the 1950s during their heyday, and don't forget that GE was developing their own manufacturing processes and insulation for their use. And EMD really didn't have anything comparable to GE in regular production, especially when it came to the industrial designs or 36" gauge locomotives. After Westinghouse left the heavy traction market, GE produced the vast majority of 36" gauge locomotives for use in the Americas.

I have no specific information on the D&S diesels, nor have I ever seen them. However, they were common GE designs and based on typical production at the time the #9 should have been built at 550 hp - which is misleading because they would have been only 420 hp traction. The traction motors should be GE763, which is a good motor but not very big. They are normally self-ventilating and a double reduction gear unit (some steel units got triple reduction). Several gear ratios were available, so that is what determines the maximum speed and continuous tractive effort. No doubt these engines have been heavily modified over the last 60 years, but additional horsepower doesn't usually increase tractive effort just allows for higher speeds. Under most conditions, the laws of railroad physics means that the #9 would be a mean SOB on nearly flat ground at under 10 mph, but not ideal for the Loop's grades and need to keep the schedule. In my limited opinion ...